Subject | Natural Science
Introduction to Evolutionary Developmental Biology ~How Dinosaurs Evolved into Birds~
The theory that birds evolved from dinosaurs, as Darwin also contended, which has been debated for more than 150 years, has been confirmed by the discovery of feathered dinosaurs. But what exactly are we to make of dinosaurs evolving into birds in the first place? It does not mean appearance changing into other animals in developmental steps like Pokemon or Godzilla.
Birds develop from a single cell, called a fertilized egg, inside an eggshell. In the same way, dinosaurs must also have developed from a single fertilized egg. Thus, the evolution of dinosaurs into birds indicates that the developmental process that formed dinosaurs changed, and animals with the developmental process that formed birds were created. Could that actually happen? In this course, we will learn the basics for contemplating how dinosaurs evolved into birds from the perspective of evolutionary developmental biology, which pursues the biological evolution mechanism in the developmental process of animals.
Content/学習内容
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We will learn the basics of embryology. That all animals are made of cells, that development occurs, and that cells differentiate will be explained.
- 1-0. Introduction
- 1-1. The Relationship between Dinosaurs and Birds
- 1-2. Living Things are Made up of Cells
- 1-3. Birth = Development: All Animals Generate from a Single Cell
- 1-4. The Basic Vertebrate Body Plan = Chikuwa
- 1-5. From Mammalian Egg to Baby
- 1-6. From Chicken Egg to Chick
- 1-7. From Single Cell to Sheet of Cells, to Chikuwa
- 1-8. Cell Lineage and Cell Differentiation
- 1-9. Cell Differentiation and Induction
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We will study the importance of proteins and genes in development and how genetic inheritance connects animals. We will also learn about terms such as genome, DNA, and gene expression.
- 2-0. Introduction
- 2-1. The Mechanism of Muscle Movement
- 2-2. The Importance of Cell Differentiation and Cell-specific Proteins
- 2-3. The Identity of Genetic Information (1): Protein Functions and Genes
- 2-4. The Identity of Genetic Information (2): the Relationship Between the Genome, DNA, and Genes
- 2-5. The Identity of Genetic Information (3): Transcriptional Regulation that Produces Specific Gene Expression
- 2-6. Examples of Differentiated Cell-specific Gene Expression
- 2-7. Reproduction: the Mechanism for Creating the Next Generation
- 2-8. Genetic Inheritance: the Mechanism for Passing Morphogenesis Information on to the Next Generation
- 2-9. From a Parent-child Relationship to a Family Tree, Then to a Phylogenetic Tree
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We will talk about the developmental process of hands and feet, particularly how fingers, or digits, develop. Furthermore, we will explain principles producing differences in animal morphology by changing the mechanisms of development.
- 3-0. Introduction
- 3-1. The Developmental Process and Morphogenesis
- 3-2. Limb Development (1): The Elongation of Limb Buds and Bone Formation
- 3-3. Limb Development (2): The ZPA
- 3-4. Limb Development (3): The shh Gene and the Concentration Gradient Theory
- 3-5. The Regulation of shh Gene Expression
- 3-6. Developmental Mechanism Shifts (1): Heterochrony
- 3-7. Developmental Mechanism Shifts (2): Heterotopy
- 3-8. Molecular Mechanisms Enabling Shifts (1): Meiosis and Recombination
- 3-9. Molecular Mechanisms Enabling Shifts (2): Mutation and Genetic Inheritance
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We will finally discuss the dinosaur-bird relationship and evolution. The avian enhancer sequence, which makes a bird a bird, was introduced into the genome during the dinosaur-to-bird evolutionary process. We will pull together what we have learned to understand what avian enhancers are.
- 4-0. Introduction
- 4-1.Structures and Morphology Specific Only to Birds
- 4-2.Limb Development and Feather Development
- 4-3.Genome Sequences Specific Only to Birds
- 4-4.Genome Sequences Specific Only to Birds: Are They Avian Enhancers?
- 4-5. How Widespread is the Use of Avian Enhancers Among Animals?
- 4-6. Are Dinosaurs Ancestors of Birds?
- 4-7. Understanding Developmental Mechanisms by Resolving Discrepancies in How the Digits are Numbered
- 4-8. The Possibility That Dinosaurs Also Used Avian Enhancers
- 4-9. Summary: The Evolution of Animal Morphology is an Accumulation of Changes in Developmental Mechanisms
Staff/スタッフ
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- Teacher
Koji TamuraTohoku University Graduate School of Life SciencesProfessor
Contact/お問合せ先
Center for the Advancement of Open Online Education, Tohoku University
Email: secretary.mooc@grp.tohoku.ac.jp